Other cases of the illness, which is relatively new to the Americas, have been reported in travelers returning home to Florida, New York, Texas and elsewhere, often after trips to the Caribbean.

Here is some key information about chikungunya and the virus that causes it.

How do you get chikungunya? Mosquitoes transmit the virus between people. The two species usually responsible, Aedes aegypti and Aedes albopictus, bite mostly during the day. In the U.S., they are found in the Southeast and in some parts of the Southwest, though Aedes albopictus also is found up through the Mid-Atlantic and in the lower Midwest.

What are the symptoms? The most common symptoms are fever and joint pain, often in the hands and feet; also possible are muscle aches, headaches, joint swelling and a rash. Symptoms, which can be severe, usually begin three to seven days after a person is bitten. Most people feel better within a week, and death is rare, though joint pain can persist.

How do you treat chikungunya? There is no specific treatment and no vaccine. Medicines like ibuprofen, naproxen, paracetamol and acetaminophen can relieve fever and pain, though.

How do you avoid getting chikungunya? To protect yourself, try to avoid being bitten. Use air conditioning or window screens. Use insect repellant, and if possible, wear long sleeves and pants. Get rid of standing water, where mosquitoes can breed.

Who is most at risk for a severe case? Newborns exposed during delivery, people 65 and older and those with high blood pressure, diabetes or heart disease are at the highest risk.

What does the name mean? It is derived from a word in the Kimakonde language, spoken in southern Tanzania, where the virus was first detected. It means to become contorted or bent, describing the stooped appearance of someone suffering from joint pain.

Where has it been reported? Outbreaks have occured in Africa, Asia and Europe and on the islands in the Indian and Pacific oceans. The first case transmitted in the Americas was reported in the Caribbean in late 2013.